Expandable material

ABSTRACT

An expandable material and articles incorporating the same are disclosed. The material includes a polymeric admixture; a blowing agent; a curing agent; a tackifier; and optionally, a filler or fiber.

The present application claims the benefit of the filing date of U.S.Provisional Application Ser. No. 60/482,897, filed Jun. 26, 2003, herebyincorporated by reference.

FIELD OF THE INVENTION

The present invention relates generally to an expandable material. Morepreferably, the present invention relates to an expandable material thatexhibits a property such as substantially homogeneous expansion, a highlevel of expansion, improved cohesiveness, a combination thereof or thelike.

BACKGROUND OF THE INVENTION

For many years, industry has been concerned with designing materialssuch as adhesives, baffle materials, structural materials or the like,which exhibit desired characteristics. As examples, the transportationindustry and, particularly, the automotive industry has been concernedwith designing expandable materials that exhibit characteristics such aslow weight, good adhesion, sound absorption, sound damping, relativelyhigh levels of expansion, homogeneous expansion, consistent orpredictable expansion or other desired characteristics. Design of suchmaterials with two or more of these characteristics can presentdifficulties however. For example, it can be difficult to provide anexpandable material that exhibits a relatively high level of expansionwithout sacrificing characteristics such as adhesion, homogeneity ofexpansion or the like. Thus, the present invention seeks to provide anexpandable material that exhibits at least one desired characteristicwithout significantly sacrificing the presence of at least one otherdesired characteristic.

SUMMARY OF THE INVENTION

Accordingly, the present invention provides an expandable material,which may be employed for sealing, baffling, reinforcing, structuralbonding or the like of a variety of structures. The material istypically an expandable adhesive material and also typically includesone or more of the following components: a polymeric admixture; an epoxyresin; a filler; a blowing agent; a curing agent; an accelerator for theblowing agent or the curing agent; a tackifier; a coagent; ananti-oxidant; combinations thereof or the like. Preferably, thepolymeric admixture includes an acrylate, an acetate or both, althoughnot required. One preferred reinforcement material is a pulped form ofaramid fiber, which can assist in flow control, sag resistance and/orself-support ability of the material.

The material may be formed according to a variety of protocols. In onepreferred method, the various components of the material are intermixedin one or more continuous or batch-type mixing processes or acombination thereof. The material may be applied (e.g., adhered) to avariety of structures, which may be formed of a variety of materialssuch as aluminum, magnesium, steel, sheet molding compound, bulk moldingcompound, thermoplastics, combinations thereof or the like. Moreover thematerial may be employed in a variety of applications such as baffling,sealing, reinforcement of the like.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is predicated upon providing an improvedexpandable material, and articles incorporating the same. The expandablematerial preferably expands upon activation by heat or other condition.Preferably, although not required, the expandable material can exhibitrelatively high levels of expansion while maintaining homogeneity ofexpansion and/or without experiencing cohesive failure. Additionally, ithas been found that the expandable material is particularly useful inapplications such as providing sound absorption, baffling or sealing toarticles of manufacture such as automotive vehicles.

In a typical application, the expandable material can assist inproviding, baffling, adhesion, sealing, acoustical damping properties,reinforcement or a combination thereof within a cavity of or upon asurface of a structure, or to one or more members (e.g., a body panel orstructural member) of an article of manufacture (e.g., an automotivevehicle).

The expandable material preferably includes a combination of three ormore of the following components:

-   -   (a) up to about 85 parts by weight of a polymeric material        admixture such as an admixture of acrylates, acetates or the        like;    -   (b) up to about 20 parts by weight epoxy resin;    -   (c) up to about 20 parts by weight of a tackifier such as a        hydrocarbon resin;    -   (d) up to about 25 parts by weight blowing agent;    -   (e) up to about 10 parts by weight curing agent; and    -   (f) up to about 40 parts by weight filler.

The expandable material of the present invention may be applied tovarious articles of manufacture for providing acoustical damping to thearticles, for sealing the articles or for providing reinforcement to thearticles. Examples of such articles of manufacture include, withoutlimitation, household or industrial appliances, furniture, storagecontainers, buildings, structures or the like. In preferred embodiments,the expandable material is applied to portions of an automotive vehiclesuch as body or frame members (e.g., a vehicle frame rail) of theautomotive vehicle. One method of the present invention contemplatesapplying the expandable material to a surface of one of the abovestructures in an unexpanded or partially expanded state and activatingthe material for expanding it to a volume greater than its volume in theunexpanded state (e.g., 1000% greater, 2000% greater, 2500% greater,3000% greater, 3500% greater or higher).

Percentages herein refer to weight percent, unless otherwise indicated.

Polymeric Material Admixture The expandable material typically includepolymeric material admixture, which may include a variety of differentpolymers, such as thermoplastics, elastomers, plastomers combinationsthereof or the like. For example, and without limitation, polymers thatmight be appropriately incorporated into the polymeric admixture includehalogenated polymers, polycarbonates, polyketones, urethanes,polyesters, silanes, sulfones, allyls, olefins, styrenes, acrylates,methacrylates, epoxies, silicones, phenolics, rubbers, polyphenyleneoxides, terphthalates, acetates (e.g., EVA), acrylates, methacrylates(e.g., ethylene methyl acrylate polymer) or mixtures thereof. Otherpotential polymeric materials may be or may include, without limitation,polyolefin (e.g., polyethylene, polypropylene) polystyrene,polyacrylate, poly(ethylene oxide), poly(ethyleneimine), polyester,polyurethane, polysiloxane, polyether, polyphosphazine, polyamide,polyimide, polyisobutylene, polyacrylonitrile, poly(vinyl chloride),poly(methyl methacrylate), poly(vinyl acetate), poly(vinylidenechloride), polytetrafluoroethylene, polyisoprene, polyacrylamide,polyacrylic acid, polymethacrylate.

The polymeric admixture typically comprises a substantial portion of theexpandable material (e.g., up to 85% by weight or greater). Preferably,the polymeric admixture comprises about 25% to about 85%, morepreferably about 40% to about 75% and even more preferably about 50% toabout 70% by weight of the expandable material.

Although not required, it is preferable for the polymeric admixture toinclude one or more acrylates. The acrylates may include, for example,simple acrylate, methyl acrylate, ethyl acrylate, butyl acrylate, vinylacrylate, copolymers or combinations thereof or the like. Moreover, anyof these acrylates may include other chemical groups such as epoxy,ethylene, butylene, pentene or the like for forming compounds such asethylene acrylate, ethylene methyl acrylate and so on, and additionallyfor forming copolymers or combinations thereof or the like. Whenincluded, the one or more acrylates typically comprise about 20% or lessto about 95% or greater, more preferably about 40% to about 85% and evenmore preferably about 55% to about 75% by weight of the polymericadmixture.

A preferred acrylate is a copolymer of butyl acrylate and methylacrylate and more particularly a copolymer of an ethylene butyl acrylateand ethylene methyl acrylate. An example of such a copolymer is soldunder the tradename LOTRYL 35BA40 and is commercially available fromATOFINA Chemical, Inc., 2000 Market Street, Philadelphia, PA 19103.Another preferred acrylate is an epoxy modified (e.g., epoxidized)acrylate copolymer. An example of such a copolymer is sold under thetradename ELVALOY 4170 and is commercially available from E. I. DupontDe Nemours and Company, 1007 Market Street, Wilmington, Del. 19898.

It is also preferable, although again, not required, that the polymericadmixture include one or more acetates. The acetates may include, forexample, acetate, methyl acetate, ethyl acetate, butyl acetate, vinylacetate, copolymers or combinations thereof or the like. Moreover, anyof these acetates may include other chemical groups such as epoxy,ethylene, butylene, pentene or the like for forming compounds such asethylene acrylate, ethylene methyl acrylate and so on and additionallyfor forming copolymers or combinations thereof or the like. Whenincluded, the one or more acetates typically comprise about 5% or lessto about 50% or greater, more preferably about 7% to about 35% and evenmore preferably about 15% to about 25% by weight of the polymericadmixture.

A preferred acetate is ethylene vinyl acetate (EVA). One example of suchan acetate is a relatively high ethylene content EVA sold under thetradename ESCORENE UL-7760, commercially available from ExxonMobilChemical, 13501 Katy Freeway, Houston, Tex. 77079-1398. Another exampleof such an acetate is a relatively low molecular weight/low melt indexEVA sold under the tradename ESCORENE UL-MV02514, commercially availablefrom Exxon Mobile Chemical, 13501 Katy Freeway, Houston, Tex.77079-1398.

Epoxy Resin

Epoxy resin is used herein to mean any of the conventional dimeric,oligomeric or polymeric epoxy materials containing at least one epoxyfunctional group. The polymer-based materials may be epoxy containingmaterials having one or more oxirane rings polymerizable by a ringopening reaction. In preferred embodiments, the expandable materialincludes up to about 20% of an epoxy resin. More preferably, theexpandable includes between about 0.1% and 10% by weight epoxy resin.

The epoxy may be aliphatic, cycloaliphatic, aromatic or the like. Theepoxy may be supplied as a solid (e.g., as pellets, chunks, pieces orthe like) or a liquid (e.g., an epoxy resin). The epoxy may include anethylene copolymer or terpolymer that may possess an alpha-olefin. As acopolymer or terpolymer, the polymer is composed of two or threedifferent monomers, i.e., small molecules with high chemical reactivitythat are capable of linking up with similar molecules.

Preferably, an epoxy resin is added to the expandable material toincrease properties such as adhesion, cohesion or the like of thematerial. Additionally, the epoxy resin may strengthen cell structurewhen the expandable material is a foamable material. One exemplary epoxyresin may be a phenolic resin, which may be a novalac type or other typeresin. Other preferred epoxy containing materials may include abisphenol-A epichlorohydrin ether polymer, or a bisphenol-A epoxy resinwhich may be modified with butadiene or another polymeric additive.

Tackifier

A variety of tackifiers or tackifying agents may be included in theexpandable material. Exemplary tackifiers include, without limitation,resins, phenolic resins (e.g., thermoplastic phenolic resins), aromaticresins, synthetic rubbers, alcohols or the like. According to onepreferred embodiment, a hydrocarbon resin 9 (e.g., a C5 resin, a C9resin, a combination thereof or the like) is employed as a tackifier.The hydrocarbon resin may be saturated, unsaturated or partiallyunsaturated (i.e., have 1, 2, 3 or more degrees of unsaturation). Oneexample of a preferred hydrocarbon resin is a coumarone-indene resin.Another example of a preferred hydrocarbon resin is sold under thetradename NORSELENE® S-105 and is commercially available from SartomerCompany, Inc., 502 Thomas Jones Way, Exton, Pa. 19341.

When used, the tackifer preferably comprises about 0.1% or less to about30% or greater, more preferably about 2% to about 25% and even morepreferably about 6% to about 20% by weight of the expandable material.Advantageously, the tackifier may be able to assist in controlling curerates for producing a more consistent or predictable expansion for theexpandable material.

Blowing Agent

One or more blowing agents may be added to the expandable material forproducing inert gasses that form, as desired, an open and/or closedcellular structure within the expandable material. In this manner, itmay be possible to lower the density of articles fabricated from thematerial. In addition, the material expansion helps to improve sealingcapability, substrate wetting ability, adhesion to a substrate, acousticdamping, combinations thereof or the like.

The blowing agent may include one or more nitrogen containing groupssuch as amides, amines and the like. Examples of suitable blowing agentsinclude azodicarbonamide, dinitrosopentamethylenetetramine,4,4_(i)-oxy-bis-(benzenesulphonylhydrazide), trihydrazinotriazine and N,N_(i)-dimethyl-N,N_(i)-dinitrosoterephthalamide.

An accelerator for the blowing agents may also be provided in theexpandable material. Various accelerators may be used to increase therate at which the blowing agents form inert gasses. One preferredblowing agent accelerator is a metal salt, or is an oxide, e.g. a metaloxide, such as zinc oxide. Other preferred accelerators include modifiedand unmodified thiazoles or imidazoles, ureas or the like.

Amounts of blowing agents and blowing agent accelerators can vary widelywithin the expandable material depending upon the type of cellularstructure desired, the desired amount of expansion of the expandablematerial, the desired rate of expansion and the like. Exemplary rangesfor the amounts of blowing agents, blowing agent accelerators or bothtogether in the expandable material range from about 0.1% by weight toabout 25%, more preferably about 2% to about 20% and even morepreferably about 7% to about 15% by weight of the expandable material.

In one embodiment, the present invention contemplates the omission of ablowing agent. Thus it is possible that the material will not be anexpandable material. Preferably, the formulation of the presentinvention is thermally activated. However, other agents may be employedfor realizing activation by other means, such as moisture, radiation, orotherwise.

Curing Agent

One or more curing agents and/or curing agent accelerators may be addedto the expandable material. Amounts of curing agents and curing agentaccelerators can, like the blowing agents, vary widely within theexpandable material depending upon the type of cellular structuredesired, the desired amount of expansion of the expandable material, thedesired rate of expansion, the desired structural properties of theexpandable material and the like. Exemplary ranges for effective amountsof the curing agents, curing agent accelerators of both together presentin the expandable material range from about 0% by weight to about 7% byweight.

Preferably, the curing agents assist the expandable material in curingby crosslinking of the polymers, epoxy resins (e.g., by reacting instoichiometrically excess amounts of curing agent with the epoxidegroups on the resins) or both. It is also preferable for the curingagents to assist in thermosetting the expandable material. Usefulclasses of curing agents are materials selected from aliphatic oraromatic amines or their respective adducts, amidoamines, polyamides,cycloaliphatic amines, (e.g., anhydrides, polycarboxylic polyesters,isocyanates, phenol-based resins (such as phenol or cresol novolakresins, copolymers such as those of phenol terpene, polyvinyl phenol, orbisphenol-A formaldehyde copolymers, bishydroxyphenyl alkanes or thelike), peroxides or mixtures thereof. Particular preferred curing agentsinclude modified and unmodified polyamines or polyamides such astriethylenetetramine, diethylenetriamine tetraethyltenepentamine,cyanoguanidine, dicyandiamides and the like. An accelerator for thecuring agents (e.g., a modified or unmodified urea such as methylenediphenyl bis urea, an imidazole or a combination thereof) may also beprovided for preparing the expandable material.

Though longer curing times are also possible, curing times of less than5 minutes, and even less than 30 seconds are possible for theformulation of the present invention. Moreover, such curing times candepend upon whether additional energy (e.g., heat, light, radiation) isapplied to the material or whether the material is cured at roomtemperature.

Filler

The expandable material may also include one or more fillers, includingbut not limited to particulated materials (e.g., powder), beads,microspheres, nanoparticles or the like. Preferably the filler includesa relatively low-density material that is generally non-reactive withthe other components present in the expandable material.

Examples of fillers include silica, diatomaceous earth, glass, clay,talc, pigments, colorants, glass beads or bubbles, glass, carbon ceramicfibers, antioxidants, and the like. Such fillers, particularly clays,can assist the expandable material in leveling itself during flow of thematerial. The clays that may be used as fillers may includenanoparticles of clay and/or clays from the kaolinite, illite,chloritem, smecitite or sepiolite groups, which may be calcined.Examples of suitable fillers include, without limitation, talc,vermiculite, pyrophyllite, sauconite, saponite, nontronite,montmorillonite or mixtures thereof. The clays may also include minoramounts of other ingredients such as carbonates, feldspars, micas andquartz. The fillers may also include ammonium chlorides such as dimethylammonium chloride and dimethyl benzyl ammonium chloride. Titaniumdioxide might also be employed.

In one preferred embodiment, one or more mineral or stone type fillerssuch as calcium carbonate, sodium carbonate or the like may be used asfillers. In another preferred embodiment, silicate minerals such as micamay be used as fillers. It has been found that, in addition toperforming the normal functions of a filler, silicate minerals and micain particular improved the impact resistance of the cured expandablematerial.

When employed, the fillers in the expandable material can range from 1%to 90% by weight of the expandable material. According to someembodiments, the expandable material may include from about 3% to about30% by weight, and more preferably about 10% to about 20% by weightclays or similar fillers.

It is contemplated that one of the fillers or other components of thematerial may be thixotropic for assisting in controlling flow of thematerial as well as properties such as tensile, compressive or shearstrength.

Other Additives

Other additives, agents or performance modifiers may also be included inthe expandable material as desired, including but not limited to a UVresistant agent, a flame retardant, an impact modifier, a heatstabilizer, a UV photoinitiator, a colorant, a processing aid, ananti-oxidant, a lubricant, a coagent, a reinforcement (e.g., chopped orcontinuous glass, glass fiber, ceramics and ceramic fibers, aramidfibers, aramid pulp, carbon fiber, acrylate fiber, polyamide fiber,polypropylene fibers, combinations thereof or the like). In onepreferred embodiment, for example, an acrylate coagent may be employedfor enhancing cure density. It is also contemplated that the expandablematerial may include about 0.10 to about 5.00 weight percent of ananti-oxidant such as a propionate (e.g., pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate)) for assisting incontrolling oxidation, cure rate or both. An example of such ananti-oxidant is sold under the tradename IRGANOX® 1010 and iscommercially available from Ciba Specialty Chemicals Company, 141Klybeckstrasse, Posffach, 4002 Basel, Switzerland.

When determining appropriate components for the expandable material, itmay be important to form the material such that it will only activate(e.g., flow, foam or otherwise change states) at appropriate times ortemperatures. For instance, in most applications, it is undesirable forthe material to be reactive at room temperature or otherwise at theambient temperature in a production environment. More typically, theexpandable material becomes activated to flow at higher processingtemperatures. As an example, temperatures such as those encountered inan automobile assembly plant may be appropriate, especially when theexpandable material is processed along with the other components atelevated temperatures or at higher applied energy levels, e.g., duringpainting preparation steps. Temperatures encountered in many coatingoperations (e.g., in a paint curing oven), for instance, range up toabout 180° C. or higher, 200° C. or higher, 250° C. or higher.

For mixing the additives, fillers or both, it may be preferable for theadditives or fillers to be mixed with a dispersant prior to mixing themwith the other ingredients of the expandable material. Such a dispersantwill typically have a relatively low molecular weight of less than about100,000 amu, more preferably less than about 50,000 amu and still morepreferably less than about 10,000 amu, although not required. Examplesof such dispersants include, without limitation, liquid waxes, liquidelastomers or the like such as ethylene-propylene rubber (EPDM),paraffins (e.g., paraffin wax).

When the material is expandable, it is possible to make a family ofmaterials according to the present invention wherein the members of thefamily have different expansion levels. Such a family is, at least inpart, may be formed by varying the amount of blowing agent, blowingagent accelerator or both. For exemplary purposes, table A is providedbelow for showing amounts of blowing agents and/or blowing agentaccelerators for one particular family that may be formed according tothe present invention along with exemplary levels of expansion formaterials in the family. TABLE A Weight Percent of Percent Volume ofBlowing Agent, Blowing Expanded Material as Compared Agent Acceleratoror Both to Non-Expanded Material Up to 1.5% or 2.0% or greater Up toAbout 300% to about 400% or greater Up to 3.0% or 3.5% or greater Up toAbout 700% to about 800% or greater Up to 5.0% or 5.5% or greater Up toAbout 1150% to about 1250% or greater Up to 7.0% or 8% or greater Up toAbout 1550% to about 1750% or greater Up to 9.0% or 10% or greater Up toAbout 2100% to about 2250% or greater Up to 13% or 14% or greater Up toAbout 2900% to about 3000% or greater

For balancing out the formulation, it may be desirable for a filler(e.g., a mineral filler) to replace the weight percent of blowing agentor blowing agent accelerator that is removed for materials having lowerexpansion. As an example, if 5 weight percent of the material is removedby removing blowing agent or accelerator, it may be desirable to replacethe 5 weight percent with filler.

Highly Preferred Embodiments and Examples

It is contemplated within the present invention that polymers or othermaterials other than those discussed above may also be incorporated intothe expandable material, e.g., by copolymerization, by blending, orotherwise. Below, exemplary formulations of the expandable material areprovided. Since they are merely exemplary, it is contemplated that theweight percents of the various ingredients may vary by ±75% or more orby ±50% or ±30%. Moreover, ingredients may be added or removed from theformulations.

EXAMPLE

Table B shows a formulation for one exemplary expandable material. TABLEB Ingredient name: % by weight Copolymer of Ethylene Butyl Acrylate and34.20 Ethylene Methyl Acrylate High Ethylene content Ethylene VinylAcetate 15.00 Epoxy Modified Acrylate Copolymer 6.00 Low MolecularWeight Ethylene Vinyl Acetate 6.00 Epoxy resin 1.00 A tackifier resin oragent (e.g., a hydrocarbon 11.70 resin, a rosin ester, a terpentine)Acrylate coagent for cure density control (e.g., 0.60 dipentaerythritolpentaacrylate) Curing agent (e.g., peroxide based curing 1.50 agent)Curing agent - 60° C.-100° C. activation 0.20 Americure curing agent0.10 Blowing agent accelerator (e.g., Zinc Oxide) 1.50 Blowing agent(e.g., azodicarbonamide) 9.00 Around 30% Aramid pulp + around 70% EPDM1.0 Pigment 0.2 Calcium carbonate 11.5 Anti-oxidant 0.5

Formation and Application of the Expandable Material

Formation of the expandable material can be accomplished according to avariety of new or known techniques. Preferably, the expandable materialis formed as a material of substantially homogeneous composition.However, it is contemplated that various combining techniques may beused to increase or decrease the concentration of certain components incertain locations of the expandable material.

According to one embodiment, the expandable material is formed bysupplying the components of the material in solid form such as pellets,chunks and the like, in liquid form or a combination thereof. Thecomponents are typically combined in one or more containers such aslarge bins or other containers. Preferably, the containers can be usedto intermix the components by rotating or otherwise moving thecontainer. Thereafter, heat, pressure or a combination thereof may beapplied to soften or liquidize the components such that the componentscan be intermixed by stirring or otherwise into a single homogenouscomposition.

According to another embodiment, the expandable material may be formedby heating one or more of the components that is generally easier tosoften or liquidize such as the polymer based materials to induce thosecomponents into a mixable state. Thereafter, the remaining componentsmay then be intermixed with the softened components. It should beunderstood that the various ingredients of the expandable material maybe combined in any desired order. Moreover, the component of thepolymeric admixture may be mixed together and then added to the otheringredients or may be combined with the other ingredients in any otherorder.

Depending upon the components used, it may be important to assure thatthe temperature of the components remains below certain activationtemperatures that might cause the expandable material to activate (e.g.,form gasses, flow or otherwise activate), cure (e.g., harden, stiffen orotherwise change states) or both. Notably, when the expandable materialcontains a blowing agent, it is typically desirable to maintain thetemperature of the expandable material below a temperature that willactivate the blowing agent during formation of the expandable materialor before the expandable material is applied to a surface.

In situations where it is desirable to maintain the expandable materialat lower temperatures it may be desirable to maintain the components ina semi-solid or viscoelastic state using pressure or a combination ofpressure and heat to intermix the components of the expandable material.Various machines have been designed to applying heat, pressure or bothto materials. One preferred machine is an extruder. According to oneembodiment of the present invention, various components may be premixedinto one, two or more pre-mixtures and introduced at one or variouslocations in a single or twin-screw extruder. Thereafter, the heat andpressure provided by the extruder mixes the expandable material in asingle generally homogeneous composition, and preferably does so withoutactivating the material.

Activation of the material may include at least some degree of foamingor bubbling in situations where the expandable material includes ablowing agent. Such foaming or bubbling can assist the expandablematerial in wetting a substrate and forming an intimate bond with thesubstrate. Alternatively, however, it shall be recognized that theexpandable material may be activated to flow without foaming or bubblingand may still substantially wet the substrate to form an intimate bond.Formation of the intimate bond will typically but not necessarily occurupon curing of the expandable material. In one embodiment, a roboticextrusion applicator is employed, e.g., of the type disclosed in U.S.Pat. No. 5,358,397, hereby incorporated by reference.

Other applications for which the present technology may be adapted oremployed as an expandable material include those of the type identifiedin U.S. Pat. Nos. 6,358,584; 6,311,452; 6,296,298, all of which arehereby incorporated by reference. The material of the present inventionmay thus be applied to a carrier, such as a molded, extruded or stampedmember (e.g., metal or plastic, foamed or unfoamed; exemplary materialsof which include aluminum, magnesium, titanium, steel, polyamide (e.g.,nylon 6 or nylon 6,6), polysulfone, thermoplastic imide, polyetherimide, polyether sulfone or mixtures thereof. Other examples ofpreferred applications are disclosed and discussed in commonly ownedpatent application titled “Fastenable Member for Sealing, Baffling, orReinforcing and Method of Forming Same”, Attorney Docket No. 1001-142P1filed on the same date herewith.

Advantageously, certain embodiments of the present invention haveexhibited relatively high levels of expansion coupled with homogeneityand/or cohesiveness during such expansion. Thus, upon expansion, theexpandable material can fill relatively large open spaces (e.g.,cavities) while exhibiting improved properties for sealing, baffling,sound absorption or the like.

The preferred embodiment of the present invention has been disclosed. Aperson of ordinary skill in the art would realize however, that certainmodifications would come within the teachings of this invention.Therefore, the following claims should be studied to determine the truescope and content of the invention.

1-24. (canceled)
 25. A method of providing baffling or sealing to anarticle of manufacture, comprising: intermixing ingredients to form anexpandable material, the ingredients including a curing, a blowing agentand an acetate, an acrylate or both; applying the expandable material toa structure of the article of manufacture; and activating the expandablematerial to expand and form a foam, the foam having a volume that is atleast 1500% greater than the volume of the expandable material in anunexpanded state; wherein the foam provides sealing, baffling or both tothe structure of the article of manufacture.
 26. A method as in claim 25wherein the expandable material is activated upon exposure to anelevated temperature and the expandable material expands to a volumethat is at least 2000% greater than the volume of the expandablematerial in an unexpanded state.
 27. A method as in claim 25 wherein thecuring agent includes a peroxide curing agent having an activationtemperature between about 60° C. and about 110° C.
 28. A method as inclaim 25 wherein the expandable material include one or more fillers andthe one or more fillers include a fibrous filler material.
 29. A methodas in claim 25 wherein the acrylate, the acetate or both are part of apolymeric admixture that is at least about 40% by weight of theexpandable material and wherein the acrylate comprises about 20% toabout 95% of the polymeric admixture and the acetate comprises about 5%to about 50% of the polymeric admixture.
 30. A method as in claim 25wherein the expandable material includes EVA and oxide and the blowingagent includes 4,4_(i)-oxy-bis-(benzenesulphonylhydrazide),azodicarbonamide or both.
 31. A method as in claim 30 wherein the oxideincludes a metal oxide.
 32. A method as in claim 25 wherein theexpandable material includes up to about 20% by weight epoxy resin. 33.A method as in claim 25 wherein the blowing agent, blowing agentaccelerator or both are at least 5.5% by weight of the expandablematerial.
 34. A method as in claim 25 wherein the blowing agent, blowingagent accelerator or both are at least 8.0% by weight of the expandablematerial.
 35. A method of providing baffling to an automotive vehicle,comprising: intermixing ingredients to form an expandable material, theingredients including curing agent, blowing agent and an acetate, anacrylate or both; applying the expandable material to a structure of thearticle of manufacture such that the material is within a cavity definedby the automotive vehicle; and activating the expandable material toexpand and form a foam, the foam having a volume that is at least 2000%greater than the volume of the expandable material in an unexpandedstate; wherein: i. the foam provides baffling or both to the structureof the automotive vehicle; ii. the expandable material is activated uponexposure to temperatures encountered in a coating operation ofautomotive assembly.
 36. A method as in claim 35 wherein the expandablematerial expands to a volume that is at least 3000% greater than thevolume of the expandable material in an unexpanded state.
 37. A methodas in claim 35 wherein the curing agent includes at least one curingagent having an activation temperature between about 60° C. and about110° C.
 38. A method as in claim 35 wherein the expandable materialincludes one or more fillers and the one or more fillers include afibrous filler material.
 39. A method as in claim 35 wherein theacrylate, the acetate or both are part of a polymeric admixture that isat least about 40% by weight of the expandable material and wherein theacrylate comprises about 20% to about 95% of the polymeric admixture andthe acetate comprises about 5% to about 50% of the polymeric admixture.40. A method as in claim 35 wherein the expandable material includes upto about 20% by weight epoxy resin.
 41. A method as in claim 35 whereinthe blowing agent, blowing agent accelerator or both are at least 5.5%by weight of the expandable material.
 42. A method as in claim 35wherein the blowing agent, blowing agent accelerator or both are atleast 8.0% by weight of the expandable material.
 43. A method ofproviding baffling to an automotive vehicle, comprising: intermixingingredients to form an expandable material, the ingredients includingcuring agent, blowing agent, fiber and EMA, EVA or both wherein thecuring agent includes a peroxide wherein the blowing agent, blowingagent accelerator or both are at least 5.5% by weight of the expandablematerial; applying the expandable material to a structure of the articleof manufacture such that the material is within a cavity defined by theautomotive vehicle; and activating the expandable material to expand andform a foam, the foam having a volume that is at least 2000% greaterthan the volume of the expandable material in an unexpanded state;wherein: i. the foam provides baffling or both to the structure of theautomotive vehicle; ii. the expandable material is activated attemperatures encountered in a coating operation during automotiveassembly; and iii. the expandable material includes up to about 20% byweight epoxy resin.
 44. A method as in claim 43 wherein the expandablematerial includes a fibrous filler material.